Intelligent lightning protection device and operation evaluation method thereof

Abstract

The invention provides an intelligent lightning protection device and an operation evaluation method thereof, the intelligent lightning protection device comprises a shell, a sleeve, a lightning protection device die body, a cushion block and a control module, the sleeve is arranged in the shell, the lightning protection device die body is arranged in the sleeve, the lightning protection device die body is internally provided with a lightning protection device element laminate formed by laminating a plurality of zinc oxide valve plates, and the zinc oxide valve plates are arranged in the lightning protection device element laminate. An electrode block is arranged below the lightning protection device element lamination body, the cushion block penetrates through the shell and the lower end of the sleeve to be embedded into the electrode block, a current transformer and a temperature sensor are arranged at the contact position of the top of the cushion block and the electrode block, and conductive screws are arranged at the top and the bottom of the shell. The current transformer and the temperature sensor are electrically connected with the control module. The current transformer and the temperature sensor are preset in the lightning protection device, so that the operation state of the lightning protection device can be monitored.

Description

Technical Field

[0001] The present invention relates to the technical field of lightning protection, and in particular to an intelligent lightning protection device and an operation evaluation method thereof. Background Art

[0002] Currently, the operating status of commonly used lightning arresters is basically monitored by discharge counters and online monitors. By detecting the leakage current and discharge times of the lightning arrester, the operating status and action of the lightning arrester can be judged. However, in the application process, online monitors and discharge counters have the following problems:

[0003] Traditional online monitoring instruments and discharge counters generally use digital or pointer displays, and rely on manual on-site data acquisition, which is inefficient and requires a large workload for inspections; the level of intelligence is low, and data is recorded and organized manually, which is a large workload, and data analysis requires manual analysis by professionals, and the evaluation is not objective enough; judging the working status of the lightning arrester based solely on leakage current and discharge counts will result in large errors in judging the operating status of the lightning arrester; in lightning arrester installation locations such as substations, lines and substations, due to the influence of high-voltage environment, the installation location is limited and observation is inconvenient.

[0004] In actual applications, the failure of lightning arresters is often related to the thermal collapse of the lightning arrester. The direct manifestation of valve aging during long-term operation of the lightning arrester is also the abnormal increase in the internal valve temperature. Summary of the Invention

[0005] In view of this, an object of the present invention is to provide an intelligent lightning protection device and an operation evaluation method thereof, so as to at least solve the above problems.

[0006] The technical solution adopted in the present invention is as follows:

[0007] The first aspect of the present application provides an intelligent lightning protection device, including a shell, a sleeve, a lightning protection device mold, a pad and a control module, the sleeve is arranged in the shell, the lightning protection device mold is arranged in the sleeve, a lightning protection device element laminate composed of multiple zinc oxide valve sheets is provided in the lightning protection device mold, an electrode block is provided below the lightning protection device element laminate, the pad passes through the shell and the lower end of the sleeve and is embedded in the electrode block, a current transformer and a temperature sensor are provided at the contact between the top of the pad and the electrode block, conductive screws are provided at the top and bottom of the shell, and the current transformer and temperature sensor are electrically connected to the control module.

[0008] Furthermore, a spring is provided inside the sleeve above the lightning protection device element laminate.

[0009] Furthermore, the conductive screw at the bottom of the shell is embedded in the lower end of the pad.

[0010] Furthermore, the current transformer and the temperature sensor are both electrically connected to cables, the cables pass through the interior of the cushion block, and the current transformer and the temperature sensor are both electrically connected to a control module disposed outside the housing through the cables.

[0011] A second aspect of the present application provides an intelligent lightning protection device operation evaluation method, which is executed in the intelligent lightning protection device mentioned in the first aspect, and includes the following steps:

[0012] Step 1: Collect the current and electrode temperature signal data in the lightning protection device and pre-process the collected signal data;

[0013] Step 2: Perform continuous Fourier transform on the current signal data and the temperature signal data to obtain the corresponding spectrum expressions;

[0014] Step 3: Set the current critical value and the maximum allowable temperature difference, and use the spectrum expressions of current and temperature to evaluate the status of the lightning protection device.

[0015] Furthermore, it is characterized in that the preprocessing of the collected signal data in step 1 is specifically: removing outliers in the signal data, filling missing values in the signal data by interpolation, and then normalizing the signal data.

[0016] Furthermore, step 2 is specifically as follows: performing continuous Fourier transform on the current signal data to obtain a spectrum expression of the current; calculating the temperature field in the lightning protection device through the temperature signal data, and performing Fourier transform on the temperature field to obtain a spectrum expression of the temperature field in the lightning protection device.

[0017] Furthermore, the temperature field in the lightning protection device is calculated using the temperature signal data as follows:

[0018] Set the heat conduction formula in the x-axis direction of the electrode sheet:

[0019]

[0020] Among them, q x,s represents the heat flux density along the x-axis, λ s is the thermal conductivity of the electrode, T s Indicates the surface temperature of the electrode;

[0021] Calculation formula for setting zinc oxide valve plate temperature:

[0022]

[0023] Where ρ is the density of zinc oxide valve material, C p is the specific heat capacity, T vis the temperature of the zinc oxide valve plate, Q is the thermal power density generated by the internal heat source, λ v is the thermal conductivity of the zinc oxide valve plate;

[0024] When the distance between the electrode sheet and the zinc oxide valve sheet is zero, the temperature conduction relationship between the electrode sheet and the zinc oxide valve sheet is established:

[0025] q x,s =q x,v

[0026]

[0027] Among them, q x,s represents the heat flux density on the electrode surface, q x,v Indicates the heat flux density on the surface of zinc oxide valve plate;

[0028] By solving the above equations, the temperature field distribution of the zinc oxide valve plate is obtained.

[0029] Furthermore, step 3 is specifically as follows: setting the current critical value, calculating the current difference X1 between the current in the lightning protection device and the current critical value; setting the maximum allowable temperature difference, calculating the temperature difference X2 between the temperature difference in the lightning protection device and the maximum allowable temperature difference; using the current difference X1 and the temperature difference X2 to evaluate the operating status of the lightning protection device through a status evaluation formula; the status evaluation formula is:

[0030] W j =C1X1+C2X2

[0031] Among them, C1 and C2 represent interference factors, which respectively reflect the influencing variables of current and temperature in state evaluation.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The present invention provides an intelligent lightning protection device and an operation evaluation method thereof. The device pre-buries the current (including leakage current and discharge current) signal and temperature detection signal of the lightning arrester in the lightning arrester, thereby realizing a new type of lightning protection device that integrates lightning protection and operation status monitoring without affecting the performance of the lightning arrester itself. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only preferred embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0035] Figure 1This is a schematic diagram of the overall structure of an intelligent lightning protection device provided by one embodiment of the present invention;

[0036] Figure 2 This is a flow chart of an intelligent lightning protection device operation evaluation method provided by another embodiment of the present invention.

[0037] Description of Figure Numbers:

[0038] 1. Housing; 2. Temperature sensor; 3. Sleeve; 4. Current transformer; 5. Cable; 6. Conductive screw; 7. Zinc oxide valve plate; 8. Electrode block; 9. Spacer. DETAILED DESCRIPTION

[0039] The technical solution of the present invention is further elaborated in detail below in conjunction with the drawings and specific embodiments of the specification. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. In the following description, reference is made to "some embodiments", which describes a subset of all possible embodiments, but it should be understood that "some embodiments" can be the same subset or different subsets of all possible embodiments, and can be combined with each other without conflict.

[0040] In the following description, numerous specific details are provided to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without one or more of these details. In other instances, certain technical features well known in the art are not described to avoid confusion with the present invention.

[0041] It should be understood that the present invention can be implemented in different forms and should not be interpreted as being limited to the embodiments proposed herein. On the contrary, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. And the purpose of the terms used herein is only to describe specific embodiments and is not intended to limit the present invention. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates another way. It should also be understood that the terms "comprising" and / or "comprising" when used in this specification determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0042] It should also be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "inner," "outer," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0043] In order to fully understand the present invention, a detailed structure will be provided in the following description to illustrate the technical solution proposed by the present invention. Optional embodiments of the present invention are described in detail below. However, in addition to these detailed descriptions, the present invention may also have other implementations.

[0044] Reference Figure 1 An embodiment of the present invention provides an intelligent lightning protection device, including a shell 1, a sleeve 3, a lightning protection device mold, a pad 9 and a control module, wherein the sleeve 3 is arranged in the shell 1, and the lightning protection device mold is arranged in the sleeve 3. A lightning protection device element laminate composed of multiple zinc oxide valve sheets 7 is provided in the lightning protection device mold, and an electrode block 8 is provided below the lightning protection device element laminate. The pad 9 passes through the shell 1 and the lower end of the sleeve 3 and is embedded in the electrode block 8. A current transformer 4 and a temperature sensor 2 are provided at the contact point between the top of the pad 9 and the electrode block 8. Conductive screws 6 are provided at the top and bottom of the shell 1, and the current transformer 4 and the temperature sensor 2 are electrically connected to the control module.

[0045] For example, the current transformer 4 and temperature sensor 2 arranged on the top of the pad 9 can detect the current and temperature in the electrode block 8. By transmitting the current signal and temperature signal to the control module for processing, the control module can judge the operating status of the lightning protection device based on the current signal and temperature signal.

[0046] A spring is provided inside the sleeve 3 above the lightning protection device component laminate.

[0047] For example, the spring can press the zinc oxide valve disc 7 below to ensure good contact between the zinc oxide valve discs 7 and prevent the arrester from receiving mechanical shock during operation.

[0048] The conductive screw 6 at the bottom of the housing 1 is embedded in the lower end of the pad 9.

[0049] The current transformer 4 and the temperature sensor 2 are both electrically connected to a cable 5 , which passes through the interior of the cushion block 9 . The current transformer 4 and the temperature sensor 2 are both electrically connected to a control module disposed outside the housing 1 through the cable 5 .

[0050] Exemplarily, the data collected by the current transformer 4 and the temperature sensor 2 are transmitted to a control module provided in the outside through the cable 5 .

[0051] Another embodiment of the present invention provides an intelligent lightning protection device operation evaluation method, comprising the following steps:

[0052] Step 1: Collect the current and electrode temperature signal data in the lightning protection device and pre-process the collected signal data;

[0053] The preprocessing of the collected signal data is specifically as follows: removing outliers in the signal data, filling missing values in the signal data by interpolation, and then normalizing the signal data.

[0054] Step 2: Perform continuous Fourier transform on the current signal data and the temperature signal data to obtain the corresponding spectrum expressions, which are as follows:

[0055] Perform continuous Fourier transform on the current signal data to obtain the spectrum expression of the current; calculate the temperature field in the lightning protection device through the temperature signal data, and perform Fourier transform on the temperature field to obtain the spectrum expression of the temperature field in the lightning protection device;

[0056] The temperature field inside the lightning protection device is calculated using temperature signal data as follows:

[0057] Set the heat conduction formula in the x-axis direction of the electrode sheet:

[0058]

[0059] Among them, q x,s represents the heat flux density along the x-axis, λ s is the thermal conductivity of the electrode, T s Indicates the surface temperature of the electrode;

[0060] Calculation formula for setting zinc oxide valve plate temperature:

[0061]

[0062] Where ρ is the density of zinc oxide valve material, C p is the specific heat capacity, T v is the temperature of the zinc oxide valve plate, Q is the thermal power density generated by the internal heat source, λ v is the thermal conductivity of the zinc oxide valve plate;

[0063] When the distance between the electrode sheet and the zinc oxide valve sheet is zero, the temperature conduction relationship between the electrode sheet and the zinc oxide valve sheet is established:

[0064] q x,s =q x,v

[0065]

[0066] Among them, q x,s represents the heat flux density on the electrode surface, q x,v Indicates the heat flux density on the surface of zinc oxide valve plate;

[0067] By solving the above equations, the temperature field distribution of the zinc oxide valve plate is obtained.

[0068] Step 3: Set the current critical value and the maximum allowable temperature difference, and use the spectrum expression of current and temperature to evaluate the status of the lightning protection device.

[0069] The current critical value is set, and the current difference X1 between the current in the lightning protection device and the current critical value is calculated; the maximum allowable temperature difference is set, and the temperature difference X2 between the temperature difference in the lightning protection device and the maximum allowable temperature difference is calculated; the current difference X1 and the temperature difference X2 are used to evaluate the operating status of the lightning protection device through the status evaluation formula; the status evaluation formula is:

[0070] W j =C1X1+C2X2

[0071] Among them, C1 and C2 represent interference factors, which respectively reflect the influencing variables of current and temperature in state evaluation.

[0072] Exemplarily, the current spectrum expression and the temperature field spectrum expression are calculated by measuring the current and temperature in the lightning protection device, and the current difference at each moment is calculated by the current spectrum expression and the set current critical value; the temperature difference between any two points in the lightning protection device is calculated by the temperature field spectrum expression, and the temperature difference is calculated by comparing it with the set maximum allowable temperature difference, and the internal operating status of the lightning arrester is evaluated by the current difference and the temperature difference using the status evaluation formula.

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An intelligent lightning protection device, characterized in that: It includes a shell, a sleeve, a lightning protection device mold, a pad and a control module. The sleeve is arranged in the shell, the lightning protection device mold is arranged in the sleeve, and a lightning protection device element laminate composed of multiple zinc oxide valve sheets is provided in the lightning protection device mold. An electrode block is provided below the lightning protection device element laminate. The pad passes through the shell and the lower end of the sleeve and is embedded in the electrode block. A current transformer and a temperature sensor are provided at the contact between the top of the pad and the electrode block. Conductive screws are provided at the top and bottom of the shell. The current transformer and temperature sensor are electrically connected to the control module.

2. The intelligent lightning protection device according to claim 1, characterized in that: A spring is arranged inside the sleeve above the lightning protection device element laminate.

3. The intelligent lightning protection device according to claim 1, characterized in that: The conductive screw at the bottom of the shell is embedded in the lower end of the pad.

4. The intelligent lightning protection device according to claim 1, characterized in that: The current transformer and the temperature sensor are both electrically connected to cables, and the cables pass through the interior of the cushion block. The current transformer and the temperature sensor are both electrically connected to a control module arranged outside the housing through the cables.

5. A method for evaluating the operation of an intelligent lightning protection device, characterized in that: The method is executed in an intelligent lightning protection device, and comprises the following steps: Step 1: Collect the current and electrode temperature signal data in the lightning protection device and pre-process the collected signal data; Step 2: Perform continuous Fourier transform on the current signal data and the temperature signal data to obtain the corresponding spectrum expressions; Step 3: Set the current critical value and the maximum allowable temperature difference, and use the spectrum expressions of current and temperature to evaluate the status of the lightning protection device.

6. The method for evaluating the operation of an intelligent lightning protection device according to claim 5, characterized in that: The preprocessing of the collected signal data in step 1 is specifically as follows: removing outliers in the signal data, filling missing values in the signal data by interpolation, and then normalizing the signal data.

7. The method for evaluating the operation of an intelligent lightning protection device according to claim 6, characterized in that: Step 2 is specifically as follows: performing continuous Fourier transform on the current signal data to obtain the spectrum expression of the current; calculating the temperature field in the lightning protection device through the temperature signal data, and performing Fourier transform on the temperature field to obtain the spectrum expression of the temperature field in the lightning protection device.

8. The method for evaluating the operation of an intelligent lightning protection device according to claim 7, characterized in that: The temperature field inside the lightning protection device is calculated using temperature signal data as follows: Set the heat conduction formula in the x-axis direction of the electrode sheet: Among them, q x,s represents the heat flux density along the x-axis, λ s is the thermal conductivity of the electrode, T s Indicates the surface temperature of the electrode; Calculation formula for setting zinc oxide valve plate temperature: Where ρ is the density of zinc oxide valve material, C p is the specific heat capacity, T v is the temperature of the zinc oxide valve plate, Q is the thermal power density generated by the internal heat source, λ v is the thermal conductivity of the zinc oxide valve plate; When the distance between the electrode sheet and the zinc oxide valve sheet is zero, the temperature conduction relationship between the electrode sheet and the zinc oxide valve sheet is established: q x,s =q x,v Among them, q x,s represents the heat flux density on the electrode surface, q x,v Indicates the heat flux density on the surface of zinc oxide valve plate; By solving the above equations, the temperature field distribution of the zinc oxide valve plate is obtained.

9. The method for evaluating the operation of an intelligent lightning protection device according to claim 8, characterized in that: Step 3 is specifically as follows: setting a current critical value, and calculating the current difference X1 between the current in the lightning protection device at each moment and the current critical value through the current spectrum expression; Set the maximum allowable temperature difference, and calculate the temperature difference X2 between the temperature difference inside the lightning protection device and the maximum allowable temperature difference through the temperature spectrum expression; use the current difference X1 and the temperature difference X2 to evaluate the operating status of the lightning protection device through the status evaluation formula; the status evaluation formula is: W j =C1X1+C2X2 Among them, C1 and C2 represent interference factors, which respectively reflect the influencing variables of current and temperature in state evaluation.

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